Plant Profile: Sunflowers

By Craig Huegel

Reprinted from The Understory, Dec. 1997–Jan. 1998

Nothing epitomizes a Florida fall better than sunflowers. This land of flowers that we call home is a sea of yellow fro October through November, and sunflowers largely are responsible. We have a great number of species and all of them contribute greatly to our wildflower flora. Below are descriptions of species native to our region of central Florida. All of these make interesting additions to your home landscape.

Southeastern sunflower (Helianthus agrestis). Southeastern sunflower is a common inhabitant of moist pinelands and wet, open sites from Pinellas County southward in Florida. Like most members ofthis genus, ithas large heads of flowers on long stalks. The outer ray flowers are bright yellow while the disk flowers in the center are flattened and brownish purple. The leaves are rather broadly oval-shaped compared to some of the similar species described below, rough to the touch on the upper surface, and primarily alternate on the stem. This sunflower may reach six feet in height. The stem is branched and hairy.

Narrow-leaved sunflower (H.nbsp;angustifolius). This and Florida sunflower are the quintessential fall sunflowers in this region of the state. It is a common resident of moist pinelands and open wet edges from north through central Florida. As the name suggests, this species has very narrow leaves. These leaves also are quite rough and are attached directly to the stem without stalks. Leaves are alternate on the stem in the top half, but opposite in the lower half. The outer petals (the ray flowers) are bright yellow while the head flowers are dark brown. This species may reach six feet or more in height and the stem is rough to the touch. [illustration left]

Beach sunflower (H. debilis). This species [illustrated at right] is quite distinctive and cannot be easily confused with the other sunflowers in our region. Beach sunflower is widely planted as an ornamental, but isnaturally occuring on coastal beaches throughout Florida. Like most coastal plants, it rarely attains much height (at most three feet) and grows outward in a somewhat creeping habit. Outer petals are bright yellow while the heads are dark brownish purple. Blooms can occur throughout the year. Leaves are a glossy green, somewhat rough and triangular in shape.

Florida sunflower (H. floridanus). In most respects, this species is similar in appearance to the narrow-leaved sunflower. A major difference is the appearance of the flowers. While the outer petals are yellow, the inner disk flowers are yellow and not dark in color. This flower also is often shorter of stature, often not exceeding three feet in height. Florid sunflower occurs in central and north Florida in moist pinelands and open areas.

Rayless sunflower (H. radula). Rayless sunflower is certainly the most distinct species of the group. Found throughout the state in moist pinelands and prairies, this species is named because it is without ray flowers. This trait means that it only has the purplish brown disk flowers. Rayless sunflower rarely reaches more than three feet in height and for most of the year it is composed of a basal rosette of thick "hairy" circular leaves. Bloom time is mostly in the summer.

Rough sunflower (H. strumosus). This is the only sunflower of our region likely to be found in dry to averge soils away from the coast. Found in a variety of upland woodlands, rough sunflower has a smooth stem that commonly reaches heights of three feet or more. The mostly opposite leaves are oval in shape, attached to the stem with distinct stalks, and rough to the touch. Both the outer ray petals and the inner disk flowers are bright yellow in color. This species occurs from north through central Florida.